Crash safety plays an important role for today's motor vehicle locks. It is in particular important that neither crash induced acceleration nor crash induced deformation leads to an accidental and unintended opening of the motor vehicle door which the motor vehicle lock is assigned to. Embodiments described in the present application relate to preventing an unintended opening of the motor vehicle door based on crash induced acceleration.
Because the outer door handle, which is connected to the motor vehicle lock via a force transmission chain, comprises an inertial mass which is not rigidly connected to the vehicle door, the outer door handle does not immediately follow the movement of the motor vehicle door which is due to the acceleration stemming from the impact. As a result, a relative movement between the outer door handle and the motor vehicle door is caused, which may correspond to an opening movement of the outer door handle and thereby lead to an unintended opening of the motor vehicle lock and accordingly of the motor vehicle door.
The known motor vehicle lock (US 2011/0181052 A1), which is the starting point for the present invention, is provided with the usual lock elements catch and pawl, wherein the pawl may be deflected into a release position by actuation of a pawl actuation lever.
To guarantee a high crash safety the known motor vehicle lock comprises a crash element, which is designed as a bendable wire. By the accelerations which occur during a crash, the crash element moves into a blocking position in which the crash element blocks further actuation of the pawl actuation lever.
One disadvantage of the known motor vehicle lock is the fact that, before the intended blocking of the pawl actuation lever takes place, the crash element has to perform the above noted movement into the blocking position. The necessity of the movement of the crash element before the intended blocking takes place leads to undesirable reaction times of the crash safety function.
Furthermore for the known motor vehicle lock, the constructional design of the force transmission chain between the door handle and the pawl appears to be challenging. This is true as in a crash situation not only the pawl actuation lever, but in fact the whole force transmission chain starting from the door handle to the pawl actuation lever it is being blocked. In order not to run the risk of an unpredictable breakage of some component in this force transmission chain, i.e., even some component other than the pawl actuation lever, it has to be designed for exceptionally high forces. This is especially true for the crash element, it being designed as a bendable wire.
One object of the invention is to improve the known motor vehicle door lock arrangement such that a cost effective constructional design is possible without reducing the resulting crash safety.